N-hydroxyalkylated polyamines, methods of making N-hydroxyalkylated polyamines, and fluids containing an N-hydroxyalkylated polyamine

ABSTRACT

N-hydroxyalkylated polyamines, methods of making N-hydroxyalkylated polyamines, and drilling fluids containing N-hydroxyalkylated polyamines are provided, in which the N-hydroxyalkylated polyamine includes Formula (I): 
                         
where R 1  and R 2  are independently a —C or —CH group; R 3  is an aliphatic hydrocarbyl; R 4  and R 5  are independently acyclic hydrocarbyls, or R 1 , R 2 , R 4 , and R 5  are covalently connected to form a cyclic hydrocarbyl; and R 6 , R 7 , R 8 , and R 9  are independently acyclic hydrocarbyls or acyclic heterohydrocarbyls.

TECHNICAL FIELD

Embodiments of the disclosure relate to N-hydroxyalkylated polyamines,methods of making N-hydroxyalkylated polyamines, and fluids containingan N-hydroxyalkylated polyamine.

BACKGROUND

Drilling fluids in the oil and gas industries perform a myriad of tasks,including cleaning wells, holding cuttings in suspension, reducingfriction, lubricating drilling tools, maintaining stability ofwellbores, and preventing fluid loss. The drilling fluids must beviscous to suspend cuttings in the fluid, and must have control of thisviscosity over a broad temperature range, as oil and gas wells can belocated in a multitude of diverse locations, for example, conditions offrom less than 0° C. in freezing permafrost zones to temperaturesexceeding 400° C. in geothermal wells.

Surfactants can be added to fluids as rheology modifiers to ensureperformance of these tasks. A surfactant refers to a compound thatreduces the surface tension or interfacial tension between two or moreliquids or between a liquid and a solid. Surfactants may provideimproved performance, including rheological performance, as additives invarious fluids, such as drilling fluids, cleaning solutions, paints andcoatings, corrosion inhibitors, and personal care formulations.Conventional surfactants include dimer diamines, dimer diacids, andesters of dimer acids. However, these compounds do not perform well overa broad temperature range and are difficult to synthesize.

SUMMARY

Accordingly, an ongoing need exists for compounds that provide improvedrheological properties for wellbore fluids over a broad range oftemperatures. Moreover, an ongoing need exists for methods ofsynthesizing compounds that have improved rheological properties over abroad temperature range. The present embodiments address these needs byproviding N-hydroxyalkylated polyamines, methods of makingN-hydroxyalkylated polyamines, and fluids containing anN-hydroxyalkylated polyamine that allow for improved rheologicalproperties over a broad temperature range.

In one embodiment, the present disclosure relates to anN-hydroxyalkylated polyamine comprising Formula (I):

where R¹ and R² are independently a —C or —CH group; R³ is an aliphatichydrocarbyl; R⁴ and R⁵ are independently acyclic hydrocarbyls, or R¹,R², R⁴, and R⁵ are covalently connected to form a cyclic hydrocarbyl;and R⁶, R⁷, R⁸, and R⁹ are independently acyclic hydrocarbyls or acyclicheterohydrocarbyls.

Another embodiment of the present disclosure relates to a method ofmaking an N-hydroxyalkylated polyamine by reacting a polyamine havingFormula (XXIV):

with a cyclic oxide to produce the N-hydroxyalkylated polyamine, whereR¹ and R² are independently a —C or —CH group; R³ is an aliphatichydrocarbyl; R⁴ and R⁵ are independently acyclic hydrocarbyls, or arecovalently connected to form a cyclic hydrocarbyl.

Another embodiment of the present disclosure relates to a drilling fluidcontaining an aqueous phase, an oleaginous phase, and anN-hydroxyalkylated polyamine comprising Formula (I):

where R¹ and R² are independently a —C or —CH group; R³ is an aliphatichydrocarbyl; R⁴ and R⁵ are independently acyclic hydrocarbyls, or R¹,R², R⁴, and R⁵ are covalently connected to form a cyclic hydrocarbyl;and R⁶, R⁷, R⁸, and R⁹ are independently acyclic hydrocarbyls or acyclicheterohydrocarbyls.

Additional features and advantages of the described embodiments will beset forth in the detailed description which follows, and in part will bereadily apparent to those skilled in the art from that description orrecognized by practicing the described embodiments, including thedetailed description which follows as well as the claims.

DETAILED DESCRIPTION

Specific embodiments of the present application will now be described.The disclosure may, however, be embodied in different forms and shouldnot be construed as limited to the embodiments set forth in thisdisclosure. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the subject matter to those skilled in the art.

Unless otherwise defined, all technical and scientific terms used inthis disclosure have the same meaning as commonly understood by one ofordinary skill in the art. The terminology used in the description isfor describing particular embodiments only and is not intended to belimiting.

As used in the specification and appended claims, the singular forms“a,” “an,” and “the” are intended to include the plural forms as well,unless the context clearly indicates otherwise.

The disclosure of any ranges in the specification and claims are to beunderstood as including the range itself and also anything subsumedwithin the range, as well as endpoints. Unless otherwise indicated, thenumerical properties set forth in the specification and claims areapproximations that may vary depending on the desired properties soughtto be obtained in embodiments of the present disclosure. Notwithstandingthat numerical ranges and parameters setting forth the broad scope ofthis disclosure are approximations, the numerical values set forth inthe specific examples are reported as precisely as possible. Anynumerical values, however, may inherently contain certain errorsnecessarily resulting from error in their respective measurements orresulting from clerical error.

As used in this disclosure, a “hydrocarbyl” refers to a chemicalcomposition consisting of carbon and hydrogen. Typically, a hydrocarbylgroup is a radical analogous to a hydrocarbon molecule with a singlemissing hydrogen (where the hydrocarbyl group is connected to anotherchemical group). As used in this disclosure, a “heterohydrocarbyl”refers to a hydrocarbon composition in which one or more carbon atomsare replaced with a heteroatom, such as O, S, N, P, or combinations ofthese.

As used in this disclosure, “aliphatic” refers to an acyclic or cyclic,saturated or unsaturated carbon compound, which is not aromatic.Further, as used in this disclosure, “aliphatic hydrocarbyl” refers toan acyclic or cyclic, saturated or unsaturated compound consisting ofcarbon and hydrogen, which is not aromatic.

As used in this disclosure, “acyclic,” such as “acyclic hydrocarbon,”“acyclic hydrocarbyl,” or “acyclic heterohydrocarbyl,” refers to ahydrocarbon moiety whose atoms do not form a ring. Conversely, as usedin this disclosure, “cyclic hydrocarbyl” refers to an aromatic oraliphatic hydrocarbon moiety with at least one ring or cyclic moiety inits structural backbone, for example, aryl or cycloalkyl moieties.

As used in this disclosure, “saturated,” refers to a hydrocarbon moietycontaining carbon atoms connected by single bonds, which does notcontain double or triple carbon-carbon bonds. Typically, a saturatedhydrocarbyl group may be analogous to an alkane with a single missinghydrogen (where the alkane is connected to another chemical group).Conversely, as used in this disclosure, “unsaturated,” refers to ahydrocarbon moiety containing at least one carbon-carbon double ortriple bond. Typically, an unsaturated hydrocarbyl group may beanalogous to an alkene or alkyne with a single missing hydrogen (wherethe alkene or alkyne is connected to another chemical group).

As used throughout the disclosure, “aqueous phase” refers to a fluidcontaining water. Similarly, “oleaginous phase” refers to a fluidcontaining, resembling, or having the properties of oil. As used in thisdisclosure, “oil,” refers to a hydrocarbon-containing liquid derivedfrom petroleum.

The term “clay,” as used in this disclosure, refers to a material thatis plastic upon wetting and hardened upon drying, containing hydrousaluminum phyllosilicates, including but not limited to talc andmontmorillonite clays, such as kaolin, bentonite, and barite.

As used in this disclosure, “N-hydroxyalkylated polyamine” refers to achemical compound having at least two nitrogen atoms, with each nitrogenatom being bonded to two hydroxyalkyl groups; thereby the compositionhas at least 4 hydroxyl moieties.

As previously stated, an ongoing need exists for compounds which provideimproved rheological properties of wellbore fluids over a broad range oftemperatures, and for methods of synthesizing compounds and fluidscontaining the compound. The present embodiments may address these needsby providing N-hydroxyalkylated polyamines, methods of makingN-hydroxyalkylated polyamines, and fluids containing anN-hydroxyalkylated polyamine. As compared to conventional drillingfluids, fluids containing the N-hydroxyalkylated polyamine of thepresent disclosure may have improved electrical stability, whilemaintaining comparable gel strength and shear stress. Additionally,fluids containing the N-hydroxyalkylated polyamine of the presentdisclosure may have improved shear stress at reduced revolutions perminute (rpm), such as 3 rpm, and high temperatures, such as at orgreater than 300° F., as compared to conventional drilling fluids thatdo not contain the N-hydroxyalkylated polyamine.

One embodiment of the present disclosure is directed toN-hydroxyalkylated polyamines in accordance with Formula (I):

In Formula (I), R¹ and R² are independently a —C or —CH group; R³ is analiphatic hydrocarbyl; R⁴ and R⁵ are independently acyclic hydrocarbyls,or R¹, R², R⁴, and R⁵ are covalently connected to form a cyclichydrocarbyl; and R⁶, R⁷, R⁸, and R⁹ are independently acyclichydrocarbyls or acyclic heterohydrocarbyls.

As previously stated, R³ is an aliphatic hydrocarbyl. R³ may be asaturated or unsaturated aliphatic hydrocarbyl. In some embodiments, R³may be a saturated or unsaturated acyclic hydrocarbyl. In someparticular embodiments, R³ may be a saturated aliphatic hydrocarbyl,such as a saturated acyclic hydrocarbyl. In one or more embodiments, R³is a saturated or unsaturated C₂-C₂₀ aliphatic hydrocarbyl group (C₂-C₂₀refers to a group having from 2 to 20 carbons). In specific embodiments,R³ is a saturated or unsaturated C₂-C₂₀ aliphatic hydrocarbyl group, ora saturated or unsaturated C₂-C₁₂ aliphatic hydrocarbyl group, or asaturated C₅-C₁₀ aliphatic hydrocarbyl group. In a specific embodiment,R³ is a saturated aliphatic hydrocarbyl. In one or more embodiments, R³may be a saturated or unsaturated C₂-C₂₀ acyclic hydrocarbyl group, or asaturated or unsaturated C₂-C₁₂ acyclic hydrocarbyl group, or asaturated C₅-C₁₀ acyclic hydrocarbyl group.

In some embodiments, at least one of R⁴ and R⁵ may independently beC₂-C₂₀ acyclic hydrocarbyls, or C₅-C₁₅ acyclic hydrocarbyls, or C₆-C₁₂acyclic hydrocarbyls. In one or more embodiments, at least one of R⁴ andR⁵ may independently be an unsaturated C₂-C₂₀ acyclic hydrocarbyls. Inother embodiments, both R⁴ and R⁵ are unsaturated C₂-C₂₀ acyclichydrocarbyls. In another embodiment, the R₃ is saturated C₅-C₁₀ acyclichydrocarbyls, and R⁴ and R⁵ independently are C₅-C₁₅ acyclic hydrocarbylchains.

In one or more embodiments, R⁴ and R⁵ of the N-hydroxyalkylatedpolyamine of Formula (I), in cooperation with the R¹ and R², may formsaturated or unsaturated cyclic hydrocarbyls. Various aromatic or cyclicmoieties are considered suitable cyclic hydrocarbyls. In one or moreembodiments, the cyclic hydrocarbyls may be selected from cyclohexane,cyclohexene, benzene, naphthalene, or decahydronapthalene. In furtherembodiments, the cyclic hydrocarbyls may be substituted with alkyl,aminoalkyl, aminoalkoxy, hydroxyl, alkoxyl, alkylthio, amino, halo,haloalkyl, silyl, phosphoryl, sulfonyl, or combinations thereof. Inother embodiments, the cyclic hydrocarbyls may be substituted with atleast one saturated or unsaturated C₂-C₂₀ acyclic hydrocarbyls. Infurther embodiments, the cyclic hydrocarbyls are substituted with atleast two acyclic hydrocarbyls.

In yet another embodiment, the cyclic hydrocarbyls are substituted withat least one C₂-C₂₀ aminoalkoxy comprising two terminal hydroxyls. Inone or more embodiments, the cyclic hydrocarbyls are selected fromFormulas (II) to (XVIII):

and (XVIII).

In Formulas (II) to (XVIII), R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, and R²¹(where applicable) independently are H, alkyl, aminoalkyl, aminoalkoxy,hydroxyl, alkoxyl, alkylthio, amino, halo, haloalkyl, silyl, phosphoryl,sulfonyl, or combinations of these. Any of the R groups R¹⁴, R¹⁵, R¹⁶,R¹⁷, R¹⁸, R¹⁹ R²⁰, and R²¹ (where applicable), may be a hydrogen, asaturated aliphatic hydrocarbyl group that is unsubstituted, or asaturated aliphatic hydrocarbyl group substituted with one or morehydroxyl, aminoalkoxy, alkoxyl, alkylthio, amino, halo, haloalkyl,silyl, phosphoryl, or sulfonyl groups. In some particular embodiments,any of R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹ R²⁰, and R²¹ (where applicable) maybe may be a saturated or an unsaturated acyclic hydrocarbyl group thatis unsubstituted or substituted with one or more hydroxyl, aminoalkoxy,alkoxyl, alkylthio, amino, halo, haloalkyl, silyl, phosphoryl, orsulfonyl groups. In some embodiments, one or more of R¹⁴, R¹⁵, R¹⁶, R¹⁷,R¹⁸, R¹⁹, R²⁰, and R²¹ independently may comprise aminoalkyl moieties,such as aminoalkoxyl moieties.

In the formulas, a wavy line

at the end of a bond refers to an open covalent bond, which may be asingle, double, or even a triple bond between that constituent and thefragment of a molecule not shown (such as R¹ and R²). In someembodiments, one or more of R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹ R²⁰, and R²¹independently may contain from 1 to 100 carbons, such as from 1 to 50, 1to 25, or 1 to 10 carbons. R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹R²⁰, and R²¹independently may contain at least one unsaturated hydrocarbyl. In oneor more embodiments, the hydrocarbyl moiety may include the formulaC_(n)H_(2n), C_(n)H_(2n-2), (C_(n)H_(2n)O)_(x)C_(n)H_(2n),(C_(n)H_(2n-2)O)_(x)C_(n)H_(2n), or (C_(n)H_(2n-2)O)_(x)C_(n)H_(2n-2),where n is an integer from 2 to 20 and x is an integer from 1 to 10.

Referring again to Formula (I), R⁶, R⁷, R⁸, and R⁹ are independentlyacyclic hydrocarbyls, or acyclic heterohydrocarbyls. In one or moreembodiments, R⁶, R⁷, R⁸, and R⁹ independently may be saturated orunsaturated straight chain or branched acyclic hydrocarbyls. For exampleand not by way of limitation, R⁶, R⁷, R⁸, and R⁹ independently mayinclude a hydrocarbyl moiety having the formula C_(n)H_(2n),C_(n)H_(2n-2), (C_(n)H_(2n)O)_(x)C_(n)H_(2n),(C_(n)H_(2n-2)O)_(x)C_(n)H_(2n), or (C_(n)H_(2n-2)O)_(x)C_(n)H_(2n-2),where n is an integer from 2 to 20 and x is an integer from 1 to 10.

In one or more additional embodiments, R⁶, R⁷, R⁸, and R⁹ independentlymay be saturated or unsaturated straight chain or branched acyclicheterohydrocarbyls. For example, R⁶, R⁷, R⁸, and R⁹ independently mayinclude a heterohydrocarbyl having the formula(C_(n)H_(2n-2)O)_(x)C_(n)H_(2n), (C_(n)H_(2n-2)O)_(x)C_(n)H_(2n-2). Insome particular embodiments, n may be an integer from 2 to 10, such asfrom 2 to 5, or 2 to 4. Additionally or alternatively, in someparticular embodiments, x may be an integer from 1 to 10, 1 to 5, 1 to4, 2 to 5, 2 to 10, or 4 to 10.

In one or more embodiments, the N-hydroxyalkylated polyamine may includeat least one of Formulas (XIX) to (XXIII):

In Formulas (XIX) to (XXIII), R⁶, R⁷, R⁸, R⁹, and, where applicable, R¹⁰and R¹¹ are independently acyclic hydrocarbyls or acyclicheterohydrocarbyls. In one or more embodiments, R⁶, R⁷, R⁸, R⁹, R¹⁰, andR¹¹ independently may be saturated or unsaturated straight chain orbranched acyclic hydrocarbyls. For example and not by way of limitation,R⁶, R⁷, R⁸, R⁹, R¹⁰, and R¹¹ independently may include a hydrocarbylmoiety having the formula C_(n)H_(2n), C_(n)H_(2n-2),(C_(n)H_(2n)O)_(x)C_(n)H_(2n), (C_(n)H_(2n-2)O)_(x)C_(n)H_(2n), or(C_(n)H_(2n-2)O)_(x)C_(n)H_(2n-2), where n is an integer from 2 to 20and x is an integer from 1 to 10. In one or more additional embodiments,R⁶, R⁷, R⁸, R⁹, R¹⁰, and R¹¹ independently may be saturated orunsaturated, straight chain or branched acyclic heterohydrocarbyls. Forexample, R⁶, R⁷, R⁸, R⁹, R¹⁰, and R¹¹ independently may include aheterohydrocarbyl having the formula (C_(n)H_(2n-2)O)_(x)C_(n)H_(2n),(C_(n)H_(2n-2)O)_(x)C_(n)H_(2n-2). In some particular embodiments, n maybe an integer from 2 to 10, such as from 2 to 5, or 2 to 4. Additionallyor alternatively, in some particular embodiments, x may be an integerfrom 1 to 10, 1 to 5, 1 to 4, 2 to 5, 2 to 10, or 4 to 10.

Further embodiments of the present disclosure include methods of makingan N-hydroxyalkylated polyamine by reacting the polyamine of Formula(XXIV) with cyclic oxide.

In Formula (XXIV), R¹-R⁵ may be in accordance with any of theembodiments previously described.

In one or more embodiments, the polyamine may have at least one ofFormulas (XXV) to (XXIX):

In one or more embodiments, the reacting step may be a ring openingepoxide reaction. Without being bound by any particular theory, theprimary amino moieties present in Formula (XXIV) may cause the ring ofthe cyclic oxide to open by nucleophilic substitution, hydroxyalkylatingthe amino group to produce an N-hydroxyalkylated polyamine, such as theN-hydroxyalkylated polyamine of Formula (I).

Any suitable cyclic oxide or mixture of cyclic oxides may be utilized inthis reaction step. As non-limiting examples, suitable cyclic oxides mayinclude ethylene oxide, propylene oxide, butene monoxide, dodecenemonoxide, isobutylene monoxide, styrene oxide, 1,2-diisobutylene oxide,2,3-diisobutylene oxide, phenyl glycidyl ether, allyl glycidyl ether,methyl glycidyl ether, ethyl glycidyl ether, vinyl cyclohexene monoxide,butadiene dioxide, 3-methyl-3,4-epoxy butene-1, butadiene monoxide,vinyl cyclohexene dioxide, glycidyl methacrylate, epichlorohydrin,dicyclopentadiene monoxide, limonene dioxide, isoprene monoxide,oxetane, diglycidyl ether of pentanediol, bis 1,1′-(3,4-epoxy-6-methylphenyl) methyl formate, the reaction product of the diglycidyl ether ofpentanediol and bisphenol A, 3,3-dimethyl oxetane, 1-epoxyethyl-3,4-epoxy cyclohexane, 3,3-diethyl oxetane, 3-ethyl-3 butyloxetane, 3-chloro-methyl-3-methyl oxetane, 3-methyl-2-ethyl oxetane,1,4-dichloro-2,3-epoxy butane, allyl epoxy stearate, and other cyclicoxides. In some particular embodiments, the cyclic oxide may be ethyleneoxide, butylene oxide, propylene oxide, or combinations of these. Insome embodiments, the cyclic oxide may be ethylene oxide.

Without being bound by any particular theory, the N-hydroxyalkylatedpolyamine may function as a surfactant, meaning that it may reduce thesurface tension between two liquids or between a liquid and a solid.Moreover, the N-hydroxyalkylated polyamine may additionally oralternatively be amphiphilic, meaning that it may have a lipophilic tail(the non-polar R groups) and one or more hydrophilic heads (polar —OHgroups). These properties may be beneficial for use as an additive inmany industries, including but not limited to drilling fluids, cleaningsolutions, paints and coatings, corrosion inhibitors, and personal careformulations.

In conventional methods, dimer diamines or dimer diacids may be used toprovide improved rheological properties in fluids. However, withoutbeing bound by any particular theory, the N-hydroxyalkylated polyamineof the present disclosure may provide an unexpectedly improved rheologywhen added to fluids as compared to conventional drilling fluids.Specifically, the N-hydroxyalkylated polyamine achieves additionalbenefits, such as improved viscosity at increased temperatures andreduced shear, such as, for instance, 3 rpm and at least 300° F., ascompared to conventional drilling fluids. Moreover, typically thesynthesis of conventional drilling fluid requires use of catalysts (suchas KOH or NaOH) and often heat (such as greater than 100° C.). Thesecatalysts create a basic environment that allows the compound toindefinitely react with a cyclic oxide (such as epoxide), until thereactive sites become too dilute to further react, or until all of theadded cyclic oxide is consumed. Unlike conventional methodology, themethods of the present disclosure may not require use of a catalyst.Instead, without being bound by any particular theory, the nucleophilicnature of the amine in Formula (XXIV) may open the ring of the cyclicoxide, eliminating the need for additional catalysts.

Furthermore, the methods of the present disclosure are, in someembodiments, self-limiting. In one or more embodiments, excess cyclicoxide may be mixed with the polyamine to produce a determinate number ofmoles of the N-hydroxyalkylated polyamine despite the number of moles ofcyclic oxide added to the polyamine.

In other embodiments, the method may further involve use of a catalystto further alkoxylate the polyamine. As mentioned, use of a catalyst,including but not limited to KOH and NaOH, may allow hydroxyalkylationto initiate and continue until all reactive sites have reacted. However,without being bound by any particular theory, when a catalyst, such asKOH or NaOH is used, the reaction may not be as efficient, andintermediary compounds may be formed. For example, the amino moietiesmay not be fully hydroxyalkylated, resulting in a partialN-hydroxyalkylated polyamine in which one or both of the amino groupsmay be partially hydroxyalkylated, or may not be hydroxyalkylated. Onepossible intermediary structure includes but is not limited in any wayto Formula XXX:

In Structure XXX, R¹, R², R³, R⁴ and R⁵ are in accordance with any ofthe previously-described embodiments. R²² is a hydrogen, or a saturatedor unsaturated aliphatic hydrocarbyl group that is unsubstituted or issubstituted with one or more hydroxyl, aminoalkoxy, alkoxyl, alkylthio,amino, halo, haloalkyl, silyl, phosphoryl, or sulfonyl groups. R²² maybe acyclic hydrocarbyls or acyclic heterohydrocarbyls. In someembodiments, R²² may be saturated or unsaturated straight chain orbranched acyclic hydrocarbyls. In some particular embodiments, R²² mayinclude a hydrocarbyl or heterohydrocarbyl moiety having the formulaC_(n)H_(2n), C_(n)H_(2n-2), (C_(n)H_(2n)O)_(x)C_(n)H_(2n),(C_(n)H_(2n-2)O)_(x)C_(n)H_(2n), or (C_(n)H_(2n-2)O)_(x)C_(n)H_(2n-2),where n is an integer from 2 to 20 and x is an integer from 1 to 10. Inother embodiments, n may be an integer from 2 to 10, such as from 2 to5, or 2 to 4. Additionally or alternatively, in some particularembodiments, x may be an integer from 1 to 10, 1 to 5, 1 to 4, 2 to 5, 2to 10, or 4 to 10.

Additional non-limiting and non-exhaustive examples of intermediarycompounds include those in accordance with Formula XXXI, XXXII, andXXXIII.

In Formula XXXI, XXXII and XXXIII, R¹, R², R³, R⁴ and R⁵ are inaccordance with any embodiments previously described. Additionally, R²²,R²³, and R²⁴ (when present), are also in accordance with any embodimentspreviously described. R²², R²³, and R²⁴ (when present), may be ahydrogen, or a saturated or unsaturated aliphatic hydrocarbyl group thatis unsubstituted or is substituted with one or more hydroxyl,aminoalkoxy, alkoxyl, alkylthio, amino, halo, haloalkyl, silyl,phosphoryl, or sulfonyl groups. R²², R²³, and R²⁴ (when present) may beacyclic hydrocarbyls or acyclic heterohydrocarbyls. In some embodiments,R²², R²³, and R²⁴ (when present) may be saturated or unsaturatedstraight chain or branched acyclic hydrocarbyls. In some particularembodiments, R²², R²³, and R²⁴ (when present) may include a hydrocarbylor heterohydrocarbyl moiety having the formula C_(n)H_(2n),C_(n)H_(2n-2), (C_(n)H_(2n)O)_(x)C_(n)H_(2n),(C_(n)H_(2n-2)O)_(x)C_(n)H_(2n), or (C_(n)H_(2n-2)O)_(x)C_(n)H_(2n-2),where n is an integer from 2 to 20 and x is an integer from 1 to 10. Inother embodiments, n may be an integer from 2 to 10, such as from 2 to5, or 2 to 4. Additionally or alternatively, in some particularembodiments, x may be an integer from 1 to 10, 1 to 5, 1 to 4, 2 to 5, 2to 10, or 4 to 10.

It should be understood that these structures are intended includeisomers (both constitutional and stereoisomers), such that R¹ may befully hydroxyalkoxylated (two hydroxyl groups bonded to the aminomoiety) or partially hydroxyalkoxylated (one hydroxyl group bonded tothe amino moiety), while R² is partially hydroxyalkoxylated (onehydroxyl group bonded to the amino moiety) or is unhydroxyalkoxylated(no hydroxyl groups bonded to the amino moiety), or alternatively, R²may be fully hydroxyalkoxylated (two hydroxyl groups bonded to the aminomoiety) or partially hydroxyalkoxylated (one hydroxyl group bonded tothe amino moiety), while R¹ is partially hydroxyalkoxylated (onehydroxyl group bonded to the amino moiety) or is unhydroxyalkoxylated(no hydroxyl groups bonded to the amino moiety).

In some embodiments, these intermediary structures may constitute lessthan or equal to 30 weight percent (wt %) of the totalN-hydroxyalkylated polyamine product. For instance, the intermediarystructures may constitute less than or equal to 20 wt %, 10 wt %, 5 wt%, or 3 wt % of the total N-hydroxyalkylated polyamine product.

Further embodiments of the disclosure are also directed to drillingfluids containing an aqueous phase, an oleaginous phase, and anN-hydroxyalkylated polyamine. The N-hydroxyalkylated polyamine may be inaccordance with any of the previously-described embodiments. In someembodiments, the drilling fluid may also contain the intermediaryproducts previously discussed. Again, these intermediary structures mayconstitute less than or equal to 30 wt % of the total N-hydroxyalkylatedpolyamine product. For instance, the intermediary structures mayconstitute less than or equal to 20 wt %, 10 wt %, 5 wt %, or 3 wt % ofthe total N-hydroxyalkylated polyamine product in the drilling fluid.

The aqueous phase may contain water, including freshwater or seawater.The aqueous phase may contain brine, including natural and syntheticbrine, such as saturated brine, or brackish water. The aqueous phase insome embodiments may use water containing organic compounds or salt.Without being bound by any particular theory, salt or other organiccompounds may be incorporated into the aqueous phase to control thedensity of the drilling fluid. Increasing the saturation of the aqueousphase by increasing the salt concentration or the level of other organiccompounds in the aqueous phase may increase the density of the drillingfluid. Suitable salts include but are not limited to alkali metalchlorides, hydroxides, or carboxylates. In some embodiments, suitablesalts may include sodium, calcium, cesium, zinc, aluminum, magnesium,potassium, strontium, silicon, lithium, chlorides, bromides, carbonates,iodides, chlorates, bromates, formates, nitrates, sulfates, phosphates,oxides, fluorides and combinations of these. In some particularembodiments, brine may be used in the aqueous phase. Without being boundby any particular theory, brine may be used to create osmotic balancebetween the drilling fluid and the subterranean formation.

In some embodiments, the drilling fluid may contain from 10 volumepercent (vol %) to 70 vol % of the aqueous phase based on the totalweight of the drilling fluid. In some embodiments, the drilling fluidmay contain from 28 pounds per barrel (lb/bbl) to 630 lbs/bbl, such asfrom 30 to 600 lbs/bbl, from 50 to 500 lbs/bbl, from 100 to 500 lb/bbl,200 to 500 lbs/bbl, or 300 to 600 lbs/bbl of the aqueous phase. A barrelis equivalent to roughly 42 U.S. gallons or 159 liters.

The oleaginous phase of the drilling fluid may comprise oil, such asnatural or synthetic liquid oil, and derivatives or fractions of these.The oleaginous phase may be or may contain diesel oil, mineral oil,aromatic hydrocarbons, hydrogenated or non-hydrogenated olefins such aspoly-alpha-olefins, alpha-olefins, linear and branched olefins,poly-diorganosiloxanes, silxoanes, organosiloxanes, esters of fattyacids, straight chain, branched or cyclical alkyl ethers of fatty acids,or combinations of any of these. The oleaginous phase may containesters, ethers, acetals, dialkylcarbonates, or combinations of any ofthese. In some embodiments, the oleaginous phase may contain mineraloils, paraffin, and oils derived from plants, such as safra oil, forexample.

The drilling fluid may contain from 30 vol % to 95 vol % of theoleaginous phase based on the total weight of the drilling fluid. Thedrilling fluid may contain from 28 lb/bbl to 810 lb/bbl of theoleaginous phase based on the total weight of the drilling fluid, suchas from 30 to 800 lb/bbl, from 50 to 800 lb/bbl, from 75 to 800 lb/bbl,or from 100 to 800 lb/bbl. In some embodiments, the drilling fluid maycontain from 200 to 800 lb/bbl, or 300 to 600 lb/bbl, or 500 to 810lb/bbl of the oleaginous phase.

The drilling fluid may, in some embodiments, be an invert (water-in-oil)emulsion in which water droplets (aqueous phase as the dispersed phase)are suspended in an oil-based fluid (oleaginous phase as the continuousphase). While water-based drilling fluids can be environmentallyfriendly and cost-efficient, they corrode metal tools and disintegrateclays and salts in the drilled zones, making them an undesirable choicefor many applications. Oil-based fluids are more compatible withtooling, but are also more costly and cause concerns with handling, asdischarging whole fluid or cuttings generated with oil-based fluids isnot permitted in many offshore-drilling areas. An invert emulsion fluidmay allow the benefits of both water-based and oil-based fluids to beutilized. However, as oil and water are incompatible, the oil and waterphases may need to be mechanically mixed under increased shear to formthe emulsion, which may be aided by the presence of suitableemulsifiers.

Embodiments of the disclosure are also directed to methods of producingdrilling fluids, for example, an invert emulsion, by mixing an aqueousphase, an oleaginous phase, and N-hydroxyalkylated polyamine. In someembodiments, the method may include mixing the aqueous phase, theoleaginous phase, and the N-hydroxyalkylated polyamine under shear. Theaqueous phase, the oleaginous phase, and the N-hydroxyalkylatedpolyamine may be mixed in accordance with the API (American PetroleumInstitute)13A: Specification for Drilling-Fluid Materials. For example,the additives may be mixed at room temperature utilizing a multi-mixerrunning at API specified speed 11,500 rpm (+/−300 rpm).

The drilling fluid may contain from 0.01 wt % to 20 wt % of theN-hydroxyalkylated polyamine based on the total weight of the drillingfluid. The drilling fluid may contain from 0.02 lb/bbl to 180 lb/bbl ofthe N-hydroxyalkylated polyamine based on the total weight of thedrilling fluid, such as from 0.02 to 150 lb/bbl, or from 0.05 to 150lb/bbl. In some embodiments, the drilling fluid may contain from 0.1 to150 lb/bbl, or from 0.1 to 100 lb/bbl, or from 1 to 100 lb/bbl of theN-hydroxyalkylated polyamine.

In some embodiments, the drilling fluid may contain at least oneadditive other than the N-hydroxyalkylated polyamine. The one or moreadditives may be any additives known to be suitable for drilling fluids.As non-limiting examples, suitable additives may include emulsifiers,weighting agents, fluid loss control agents, lost circulation controlagents, other surfactants, antifoaming agents, supplemental emulsifiers,weighting agent, fluid loss additives, other viscosity adjusters, analkali reserve, specialty additives, and combinations of these.

In some embodiments, the drilling fluid may contain from 0.01 wt % to 20wt % of the one or more additives based on the total weight of thedrilling fluid. The drilling fluid may contain from 0.02 lb/bbl to 180lb/bbl of the one or more additives based on the total weight of thedrilling fluid, such as from 0.02 to 150 lb/bbl, or from 0.05 to 150lb/bbl. In some embodiments, the drilling fluid may contain from 0.1 to150 lb/bbl, or from 0.1 to 100 lb/bbl, or from 1 to 100 lb/bbl of theone or more additives.

As previously mentioned, in some embodiments, the drilling fluid of thepresent disclosure may not contain clay, or may contain reduced amountsof clay, while still producing a viscous drilling fluid. In someembodiments, the drilling fluid may contain less than or equal to 0.5lb/bbl of clay, such as less than or equal to 0.1 lb/bbl, 0.05 lb/bbl,or 0.02 lb/bbl. In some embodiments, the clay is treated withhydrophobicizing agents to become lyophilic. Such clays are referred toas organophilic clays and are added to drilling fluids which haveoleaginous phase as the continuous phase.

Embodiments of the disclosure may also relate to methods of using thedrilling fluid. The drilling fluid may be in accordance with any of theembodiments previously described. In some embodiments, the drillingfluid may be pumped into a subterranean formation. Pumping may involveinjecting the drilling fluid into the subterranean formation, which insome embodiments, may be a well. The drilling fluid may be recirculatedfrom the wellbore to surface, passed through filters to remove solidssuch as drill cuttings, reconditioned with suitable additives to adjustrheology, and circulated back into the wellbore for further drilling.

While embodiments of the drilling fluid may be used in hydraulicfracturing processes in the oil and gas industry, the drilling fluid mayalso be used in other industries. For instance, the fluid may, in someembodiments, be used to stimulate groundwater wells, to precondition orinduce rock cave-ins for mining operations, to dispose of waste byinjecting it deeply into rock, to measure stresses in the Earth's crust,for electricity generation in enhanced geothermal systems, and toincrease injection rates for the geologic sequestration of CO₂.

EXAMPLES

To demonstrate the improved rheological properties of the drillingfluids containing N-hydroxyalkylated polyamines, several tests wereperformed comparing a drilling fluid with N-hydroxyalkylated polyaminerheology modifier (Example 1) versus a drilling fluid containing acommercial dimer diamine rheology modifier (Comparative Example 1) and adrilling fluid containing a commercial dimer acid rheology modifier(Comparative Example 2). The formulations for these drilling fluidexamples are provided in Tables 1. Each drilling fluid example is thesame with the exception of the rheology modifier composition.

TABLE 1 Composition for Comparative Examples 1 and 2 and Example 1Component Amount Diesel 0.62 barrels (bbl) GELTONE ® 2 pounds per barrel(lb/bbl) Lime 6 lb/bbl VERSAMUL 8 lb/bbl VERSACOAT 4 lb/bbl Water 0.14bbl CaCl₂ 21.2 lb/bbl VERSATROL 4 lb/bbl Barite 224 lb/bbl REV DUST 2lb/bbl Rheology modifier 2 lb/bbl

In Table 1, “bbl” stands for barrels, equivalent to roughly 42 U.S.gallons or 159 liters. Likewise, “lb/bbl” stands for pounds per barrel.GELTONE® V refers to an organophilic clay viscosifier, commerciallyavailable from Halliburton (Ontario, Calif.). Lime refers to calciumoxide, CaO. VERSAMUL refers to a multi-purpose emulsifier, commerciallyavailable from Schlumberger (Houston, Tex.). VERSACOAT refers to awetting agent and secondary emulsifier, also commercially available fromSchlumberger (Houston, Tex.). CaCl₂ refers to calcium chloride, whichcan be used to provide osmotic wellbore stability. VERSATROL refers toan asphalt used for high-temperature high-pressure (HTHP) filtrationcontrol, commercially available from Schlumberger (Houston, Tex.).Barite refers to a dense sulfate mineral having the formula BaSO₄,commonly used to add weight to drilling fluids. REV DUST refers to afriction reducing material composted of small dust-like particles ofcalcium montmorillonite clay, commercially available from Milwhite, Inc.(Brownsville, Tex.).

Comparative Example 1 included Priamine™ 1074, a commercial dimerdiamine produced by Croda International PLC, as its Rheology Modifier.

The Example 1 N-hydroxyalkylated polyamine was produced by reacting thePriamine™ 1074 with ethylene oxide. The commercial dimer diamine(Priamine 1074) was added to a 500 milliliter (mL) Parr reactor whichwas sealed and subsequently sparged with nitrogen for one hour at 120°C. to drive out any oxygen and water from the solution. The system wasthen sealed and bled to atmospheric pressure. Ethylene oxide was addedvia a swagelock quick connect from a lecture bottle containing 99.9%ethylene oxide. The mass of oxide was determined by subtraction of thetared lecture bottle. As ethylene oxide was added, the pressure in thevessel increased, and the ethylene oxide reacted and was converted froma gas phase into a liquid phase, causing a drop in pressure. Ethyleneoxide was added until the theoretical maximum of 4 moles of ethyleneoxide to one mole of priamine or a priamine to ethylene oxide weightratio of 1:0.36 was reached. When other amine amines are used asreactants, the theoretical maximum of hydroxyethylating agent to theprimary amine groups in the molecule is a molar ratio of 2:1. Then thereaction was allowed to continue for 1 hour before cooling down. Anyexcess pressure was bled off through a caustic solution to scrub anypotential excess ethylene oxide. As shown in the following reactionmechanism, the amines of the dimer diamine reacted by epoxide ringopening to form the N-hydroxyalkylated polyamine.

Comparative Example 2 included a UNIDYME™ 18 dimer diacid from KratonCorporation as the Rheology Modifier. The other additives of thedrilling fluid are provided in Table 1. The drilling fluids (ComparativeExamples 1 and 2 and Example 1) were mixed in accordance with the API13A: Specification for Drilling-Fluid Materials. Specifically, theadditives were mixed at room temperature utilizing a multi-mixer runningat API specified speed 11,500 rpm (+/−300 rpm). The additives were addedat room temperature and pressure, one at a time, allowing 5 minutes ofmixing between each addition. The only exception is that water and CaCl₂were premixed and added as a brine to the drilling fluid.

Example 1 and Comparative Examples 1 and 2 were evaluated based onelectrical stability, gel strength, and shear stress, which were allmeasured according to industry standard API 13B-2: Recommended Practicefor Field Testing Oil-Based Drilling Fluids. For the electricalstability (ES) test, an electrical field is applied and the voltagerecorded is the voltage required to complete the circuit, which can onlyoccur when the emulsion breaks. Thus, the greater the voltage, thestronger the emulsion. Electrical stability was measured using a Fann 23electrical stability meter before and after aging 16 hours at atemperature of 350° F. The 10 second and the 10 minute gel strengthswere measured using a Fann 35 rotational coutte type viscometer withoutrotation (static conditions). The shear stress values were measured at 3rpm and various temperatures using a Fann 77, which is a hightemperature, high pressure (HTHP) rotational coutte type rheometer.

TABLE 2 Rheological Properties of the Drilling Fluids ComparativeComparative Property Example 1 Example 1 Example 2 Electrical stability1068 V 747 V 299 V before aging Electrical stability  564 V 380 V 157 Vafter aging (350° F. for 16 hours) Gel Strength -   8 lb_(f)/100ft²  7lb_(f)/100ft₂  2 lb_(f)/100ft² 10 seconds Gel Strength -  11lb_(f)/100ft²  19 lb_(f)/100ft₂  3 lb_(f)/100ft² 10 minutes Shear Stressat 3 rpm   8 lb_(f)/100ft²  9 lb_(f)/100ft₂  1 lb_(f)/100ft² and 150° F.Shear Stress at 3 rpm   7 lb_(f)/100ft²  7 lb_(f)/100ft₂  1lb_(f)/100ft² and 200° F. Shear Stress at 3 rpm   6 lb_(f)/100ft²  5lb_(f)/100ft₂  1 lb_(f)/100ft² and 250° F. Shear Stress at 3 rpm   7lb_(f)/100ft²  3 lb_(f)/100ft₂  2 lb_(f)/100ft² and 350° F.

In Table 2, V stands for volts, and lb_(f) stands for pounds of force,and lb_(f)/ft₂ stands for pounds of force per square foot. As shown inTable 2, Example 1 had greater electrical stability before and afteraging relative to Comparative Examples 1 and 2. This demonstrates thatthe N-hydroxyalkylated polyamine yields a more stable invert emulsiondrilling fluid 1 than the comparatives. Moreover, the 10 sec gelstrength for Example 1 (N-hydroxyalkylated polyamine rheology modifier)was similar to the Comparative Example 1 (dimer diamine); however,Comparative Example 1 showed a much larger increase at 10 minutesrelative to Example 1. This large increase is undesirable as it canindicates a solid (gel) structure buildup in the drilling mud. Also, theshear stress values at the 3 rpm reading shows that as temperatureincreases, Comparative Examples 1 and 2 (the dimer diamine and the dimeracid, respectably) had significantly lower shear stress values,indicating a loss of rheological properties. In contrast, Example 1 (theN-hydroxyalkylated polyamine) still showed relatively stable shearstress as the temperature increased.

It should be apparent to those skilled in the art that variousmodifications and variations may be made to the embodiments describedwithin without departing from the spirit and scope of the claimedsubject matter. Thus, it is intended that the specification cover themodifications and variations of the various embodiments described withinprovided such modification and variations come within the scope of theappended claims and their equivalents.

It is noted that one or more of the claims utilize the term “where” as atransitional phrase. For the purposes of defining the presenttechnology, it is noted that this term is introduced in the claims as anopen-ended transitional phrase that is used to introduce a recitation ofa series of characteristics of the Formula and should be interpreted inlike manner as the more commonly used open-ended preamble term“comprising.”

What is claimed is:
 1. An N-hydroxyalkylated polyamine comprisingFormula (I):

where: R¹ and R² are independently a —C or —CH group; R³ is an aliphatichydrocarbyl; at least one of R⁴ and R⁵ are unsaturated C₂-C₂₀ acyclichydrocarbyls; and R⁶, R⁷, R⁸, and R⁹ are independently acyclichydrocarbyls or acyclic heterohydrocarbyls.
 2. The N-hydroxyalkylatedpolyamine of claim 1, where R³ is a saturated or unsaturated C₂-C₂₀acyclic hydrocarbyl.
 3. The N-hydroxyalkylated polyamine of claim 1,where both R⁴ and R⁵ are unsaturated C₂-C₂₀ acyclic hydrocarbyls.
 4. TheN-hydroxyalkylated polyamine of claim 1, where R³ is a saturated C₅-C₁₀acyclic hydrocarbyl, and R⁴ and R⁵ independently are C₅-C₁₅ acyclichydrocarbyls.
 5. A drilling fluid comprising: an aqueous phase; anoleaginous phase; and an N-hydroxyalkylated polyamine comprising Formula(I):

where: R¹ and R² are independently a —C or —CH group; R³ is an aliphatichydrocarbyl; R⁴ and R⁵ are independently acyclic hydrocarbyls, or R¹,R², R⁴, and R⁵ are covalently connected to form a cyclic hydrocarbyl;and R⁶, R⁷, R⁸, and R⁹ are independently acyclic hydrocarbyls or acyclicheterohydrocarbyls.
 6. The drilling fluid of claim 5, where R³ is asaturated or unsaturated C₂-C₂₀ acyclic hydrocarbyl group or at leastone of R⁴ and R⁵ are unsaturated C₂-C₂₀ acyclic hydrocarbyls.
 7. Thedrilling fluid of claim 5, where Formula (I) comprises unsaturated orsaturated cyclic hydrocarbyls formed from R¹, R², R⁴ and R⁵, the cyclichydrocarbyls being selected from cyclohexane, cyclohexene, benzene,naphthalene, or decahydronapthalene.
 8. The drilling fluid of claim 7,where the cyclic hydrocarbyls are substituted with one or more of alkyl,aminoalkyl, aminoalkoxy, hydroxyl, alkoxyl, alkylthio, amino, halo,haloalkyl, silyl, phosphoryl, sulfonyl, saturated or unsaturated C₂-C₂₀acyclic hydrocarbyls, or combinations thereof.
 9. The drilling fluid ofany of claim 7, where the cyclic hydrocarbyls are substituted with atleast two acyclic hydrocarbyls or at least one C₂-C₂₀ aminoalkoxycomprising two terminal hydroxyls.
 10. An N-hydroxyalkylated polyaminecomprising Formula (I):

where: R¹ and R² are independently a —C or —CH group; R³ is an aliphatichydrocarbyl; both R⁴ and R⁵ are unsaturated C₂-C₂₀ acyclic hydrocarbyls;and R⁶, R⁷, R⁸, and R⁹ are independently acyclic hydrocarbyls or acyclicheterohydrocarbyls.
 11. The N-hydroxyalkylated polyamine of claim 10,where R³ is a saturated C₅-C₁₀ acyclic hydrocarbyl, and R⁴ and R⁵independently are C₅-C₁₅ acyclic hydrocarbyls.
 12. TheN-hydroxyalkylated polyamine of claim 10, where R³ is a saturated orunsaturated C₂-C₂₀ acyclic hydrocarbyl.
 13. An N-hydroxyalkylatedpolyamine comprising Formula (I):

where: R¹ and R² are independently a —C or —CH group; R³ is a saturatedC₅-C₁₀ acyclic hydrocarbyl; R⁴ and R⁵ are independently are C₅-C₁₅acyclic hydrocarbyls; and R⁶, R⁷, R⁸, and R⁹ are independently acyclichydrocarbyls or acyclic heterohydrocarbyls.
 14. An N-hydroxyalkylatedpolyamine comprising Formula (I):

where: R¹ and R² are independently a —C or —CH group; R³ is an aliphatichydrocarbyl; Formula (I) comprises unsaturated or saturated cyclichydrocarbyls formed from R¹, R², R⁴ and R⁵, the cyclic hydrocarbylsbeing selected from cyclohexane, cyclohexene, benzene, naphthalene, ordecahydronapthalene; the cyclic hydrocarbyls are substituted with atleast two acyclic hydrocarbyls; and R⁶, R⁷, R⁸, and R⁹ are independentlyacyclic hydrocarbyls or acyclic heterohydrocarbyls.
 15. TheN-hydroxyalkylated polyamine of claim 14, where R³ is a saturated orunsaturated C₂-C₂₀ acyclic hydrocarbyl.
 16. The N-hydroxyalkylatedpolyamine of claim 14, where the cyclic hydrocarbyls are substitutedwith one or more of an alkyl, aminoalkyl, aminoalkoxy, hydroxyl,alkoxyl, alkylthio, amino, halo, haloalkyl, silyl, phosphoryl, sulfonyl,saturated or unsaturated C₂-C₂₀ acyclic hydrocarbyls, or combinationsthereof.
 17. The N-hydroxyalkylated polyamine of claim 14, where thecyclic hydrocarbyls are substituted with at least two acyclichydrocarbyls.
 18. The N-hydroxyalkylated polyamine of claim 14, wherethe cyclic hydrocarbyls are substituted with at least one C₂-C₂₀aminoalkoxy comprising two terminal hydroxyls.